LCC-S Compensated Multiphase Wireless Power Transfer System with LC Resonant Circuits for Current Balancing

To improve the current rating of a high-frequency inverter, multiple phases can be paralleled. Passive paralleling is normally adopted due to its simplicity and effectiveness to balance the phase currents. In this paper, a novel passive current balancing method is proposed to introduce an external LC resonant network between both adjacent phases. In this way, only a small inductance is needed to obtain a very large equivalent impedance to suppress unbalanced currents, and the space inductor structure is easy to expand to multi-phase. The inductor-capacitor-capacitor series (LCC-S) compensated wireless power transfer (WPT) system for electric vehicles is adopted as the application scenario. An experimental prototype is built to verify the effectiveness of the proposed current sharing method.